Boil vs Cyst

Boil

Cyst

A boil, also called a furuncle, is a deep folliculitis, infection of the hair follicle. It is most commonly caused by infection by the bacterium Staphylococcus aureus, resulting in a painful swollen area on the skin caused by an accumulation of pus and dead tissue. Boils which are expanded are basically pus-filled nodules. Individual boils clustered together are called carbuncles. Most human infections are caused by coagulase-positive S. aureus strains, notable for the bacteria's ability to produce coagulase, an enzyme that can clot blood. Almost any organ system can be infected by S. aureus. –Editor's choicemore

A cyst is a closed sac, having a distinct membrane and division compared to the nearby tissue. Hence, it is a cluster of cells that have grouped together to form a sac (not unlike the manner in which water molecules group together, forming a bubble); however, the distinguishing aspect of a cyst is the cells forming the "shell" of such a sac, being distinctly abnormal (in both appearance and behaviour) when compared to all surrounding cells for that given location. It may contain air, fluids, or semi-solid material. A collection of pus is called an abscess, not a cyst. Once formed, a cyst may sometimes resolve on its own. Whether a cyst that fails to resolve may need to be removed by surgery will depend on what type of cyst it is and where in the body it has formed. –Editor's choicemore